Town Supervisor Laura Gillen announced Thursday that all town beaches will remain open an additional hour this weekend in anticipation of large crowds expected to hit the beach during an excessive heat wave.

Long Beach, meanwhile, announced Friday that its beaches would be extended an additional hour Saturday and Sunday, and the city's Beach Patrol is preparing for huge crowds and increasing its emergency response crews.

Gillen said that the town’s nine beaches — Atlantic Beach Estates, Civic Beach, East Atlantic Beach, Harbor Isle Beach, Hewlett Point Park, Lido Beach Town Park, Lido West Town Park , Town Park at Point Lookout and Town Park at Sands — will be extended to 7 p.m. from Friday to Sunday.

Forecasters said that Long Island is under an excessive heat warning this weekend, with temperatures in the mid-90s Saturday and Sunday, according to Newsday. Still, forecasters said that the heat will be “dangerous” because the temperatures will feel like 100 to 110 degrees.

"The Town of Hempstead is expecting a huge influx of residents and visitors coming to our five miles of beaches during the heat wave,” Gillen said in a statement. “In preparation, over 500 Town of Hempstead lifeguards are readying the town’s pools and beaches for tens of thousands of families looking to stay cool and beat the heat. Town of Hempstead beaches will remain open an extra hour with lifeguards on duty in order to help provide added relief during this scorcher.”

"If the weather is cloudy on Sunday, we may recalibrate, but the plan now is for lifeguards to work an extra hour, between 6 to 7 p.m. both days," Long Beach Acting City Manager Rob Agostisi said.

Long Beach Lifeguard Chief Paul Gillespie said he’s expecting massive crowds this weekend. Long Beach has 125 to 150 lifeguards on duty during the weekends, Gillespie said, and swimming is prohibited after 6 p.m., when lifeguards are no longer on duty. Long Beach has an after-hours an emergency team consisting of eight lifeguards and two rescue trucks on call after hours.

“If this beach is packed, I will keep the entire patrol on, if it warrants,” he said. “We’ re keeping extra trucks for our emergency response team, with about 10 extra guys.”

According to the National Weather Service, the heat warning will remain in effect from 6 a.m. Saturday to 8 p.m. Sunday, with the heat index reaching 110 degrees. An excessive heat warning is issued when the combination of heat and humidity is expected to make it feel like it is 105 degrees or greater, the agency said. Seniors and those with chronic health problems or mental health conditions are at increased risk.

“Take extra precautions if you work or spend time outside,” the weather service said. “When possible, reschedule strenuous activities to early morning or evening. Know the signs and symptoms of heat exhaustion and heat stroke. Wear light-weight and loose-fitting clothing when possible, and drink plenty of water.”

On its website, the city said that the Long Beach Public Library has been designated a cooling area during operational hours.

"Use air conditioning to stay cool at home or go to a place that has air conditioning," the city advised residents. "Check on vulnerable friends, family members and neighbors."